Shipman is the great jeweller who has his place of
business in South Audley Street. By the last post there came a letter
with the Brighton postmark, and marked 'urgent,' for Mr. Knopf, and he
(Robertson) was just wondering if he should run over to No. 26 with it,
when his master returned. He gave one glance at the contents of the
letter, asked for his A.B.C. Railway Guide, and ordered him (Robertson)
to pack his bag at once and fetch him a cab.

"'I guessed what it was,' continued Robertson after another violent fit
of sneezing. 'Mr. Knopf has a brother, Mr. Emile Knopf, to whom he is
very much attached, and who is a great invalid. He generally goes about
from one seaside place to another. He is now at Brighton, and has
recently been very ill.

"'If you will take the trouble to go downstairs I think you will still
find the letter lying on the hall table.

"'I read it after Mr. Knopf left; it was not from his brother, but from
a gentleman who signed himself J. Collins, M.D. I don't remember the
exact words, but, of course, you'll be able to read the letter--Mr. J.
Collins said he had been called in very suddenly to see Mr. Emile Knopf,
who, he added, had not many hours to live, and had begged of the doctor
to communicate at once with his brother in London.

"'Before leaving, Mr. Knopf warned me that there were some valuables in
his desk--diamonds mostly, and told me to be particularly careful about
locking up the house. He often has left me like this in charge of his
premises, and usually there have been diamonds in his desk, for Mr.
Knopf has no regular City office as he is a commercial traveller.'

"This, briefly, was the gist of the matter which Robertson related to
the inspector with many repetitions and persistent volubility.

"The detective and inspector, before returning to the station with their
report, thought they would call at No. 26, on Mr. Shipman, the great
jeweller.

"You remember, of course," added the man in the corner, dreamily
contemplating his bit of string, "the exciting developments of this
extraordinary case. Mr. Arthur Shipman is the head of the firm of
Shipman and Co., the wealthy jewellers. He is a widower, and lives very
quietly by himself in his own old-fashioned way in the small Kensington
house, leaving it to his two married sons to keep up the style and
swagger befitting the representatives of so wealthy a firm.

"'I have only known Mr. Knopf a very little while,' he explained to th